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WWUS20 KWNS 211630

SEL0

SPC WW 211630

IAZ000-MNZ000-NEZ000-SDZ000-220000-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 460

NWS Storm Prediction Center Norman OK

1135 AM CDT Mon Aug 21 2017



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northwest Iowa

  Southwest Minnesota

  Northeast Nebraska

  Southeast South Dakota



* Effective this Monday morning and evening from 1135 AM until

  700 PM CDT.



* Primary threats include...

  Scattered damaging winds and isolated significant gusts to 75

    mph possible

  Scattered large hail and isolated very large hail events to 2

    inches in diameter possible



SUMMARY...Cluster of severe storms over south-central South Dakota

should continue east-southeast with additional storm development

possible to its south and east. A swath of large hail and damaging

winds is expected this afternoon.



The severe thunderstorm watch area is approximately along and 75

statute miles north and south of a line from 45 miles south of

Chamberlain SD to 30 miles north of Storm Lake IA. For a complete

depiction of the watch see the associated watch outline update

(WOUS64 KWNS WOU0).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A Severe Thunderstorm Watch means conditions are

favorable for severe thunderstorms in and close to the watch area.

Persons in these areas should be on the lookout for threatening

weather conditions and listen for later statements and possible

warnings. Severe thunderstorms can and occasionally do produce

tornadoes.



&&



OTHER WATCH INFORMATION...CONTINUE...WW 459...



AVIATION...A few severe thunderstorms with hail surface and aloft to

2 inches. Extreme turbulence and surface wind gusts to 65 knots. A

few cumulonimbi with maximum tops to 550. Mean storm motion vector

29030.



...Grams

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